J. P. Cole, Military Instructors Manual
“ Remember that it is of the utmost importance that the machine gun be invisible, so the firing emplacements must be made outside of the shelter, but near enough for the gun to be brought out instantly and put into action. All communicating trenches leading to the firing emplacement must be concealed. Enough emplacements should be built to avoid firing daily from the emplacements especially reserved for cases of attack. Do not place too many machine guns in the first line; in case of a violent bombardment they are sure to be destroyed. ”
